Dielectric elastomer actuators generally include a layer of electro active polymer (EAP) sandwiched between a pair of compliant electrodes. The compliant electrodes can be designed to be able to comply with the deformations of the elastomer. A voltage difference can be applied between the compliant electrodes, which induces compression in thickness, and stretching in area of the polymer film. The electrodes in the dielectric elastomer actuators expand in area in addition to coming closer together as the polymer film thickness decreases. As the elastomer layer deforms at almost constant volume, the layer stretches in the perpendicular directions, requiring compliant electrodes. Such designs may be utilized for sensing or for converting mechanical energy into electrical energy.
A majority of prior dielectric elastomer actuator designs utilize a uniform dielectric elastomer with compliant electrodes. The voltage difference applied on the compliant electrodes squeeze the elastomer layer and produces an actuation mechanism. The uniform dielectric elastomer deforms due to an applied electrostatic force and stretches in perpendicular directions. Such uniform dielectric elastomer exhibits a very low elastic stiffness and high dielectric constants. Hence, in order to increase the actuation force, very thin layers of elastomer are required. Similarly, the fabrication of such thin layers by molding or by deposition on a substrate and their subsequent stripping from the substrate is difficult. Also, the fabrication of actual design is incompatible with reel-to-reel high volume fabrication methods due to long curing times. Often several hours are required for the elastomer layer.
Based on the foregoing it is believed that a need exists for an improved patterned dielectric elastomer based actuator, sensor and generator with rigid electrodes as described in greater detail herein.